<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>028-数据转换-String函数.html</title>
</head>
<body>
	
</body>
<script>
	// var a = null;

	// var a = undefined;
	var a = true;

	console.log("a1:::",a);
	console.log(typeof a);

	var b = String(a);

	console.log("b:::",b);
	console.log(typeof b);

	var c = undefined;

	console.log(c + "");
	console.log(typeof (c + ""));
</script>
</html>